Spell Checker
I was traing a customer a few years ago in MS Word. She had a particularly objectional manager who used to type everything in upper case and then send it to her to spellcheck and re-type in senteence case
This was particularly inefficient so I said I would show her how to change case next time.
The following morning her sent her another report to re-type on Borehole extraction in Norfolk.
I duly showed her how to change case and suggested she run a spell checker. Timidly she referred to him first. He said run your spell checker but I do not make mistakes.
We ran the spell checker and it changed Borehole to Brothel. She then submitted the report to all interested parties.